The GAIN program will complete a 600,000 tag SNP genome-wide association scan of 956 parent-child trios from the PI's International Multi-site ADHD Genetics (IMAGE) project. In this proposal we are requesting funds for the analysis of these data. The overarching aim of this proposal is to complete a comprehensive analysis of the whole genome scan (WGAS) data in a manner that will provide insights into the genetic etiology of ADHD and associated features. We will do this by completing the following: 1) assessing the association of GAIN SNP's with the ADHD diagnostic phenotype, 2) Imputing genotypes for siblings in the GAIN trio families, 3) Assessing the association of GAIN SNP's with the quantitative ADHD phenotypes, 4) conducting copy number analyses, 5) assessing parent of origin effects; 6) assessing season of birth effects and 7) testing for epistasis. The IMAGE project is now in the process of creating an international resource for molecular genetic studies of ADHD by sharing the study's clinical and genetic data with the scientific community through the NIMH genetic data repositories. All clinical and DNA data from our samples has been sent to the NIMH DNA and clinical data repositories for release to the scientific community. All genotype data generated by the GAIN whole genome association scan will be made available to the scientific community by GAIN as soon as the genotypes are completed. [unreadable] [unreadable] [unreadable]